Anterior myocardial infarctions in dogs have been studied by computed tomography in order to explore the potential of this modality to detect and quantitate ischemic myocardial lesions. Infarcts can be detected by non-enhanced, non-gated computed tomography although the size of the infarcted area was underestimated. We also found excellent correlation between the size of the infarction as demonstrated by contrast enhanced intravenous computed tomography and postmortem anatomic measurements. Late contrast enhancement of the infarcted area is dose dependent, requiring 2 ml or more of Renographin 76 or Hypaque 75. Regional thinning of myocardial wall as detected by computed tomography is a sensitive sign of older myocardial infarctions.